Earnings vs income? There’s a difference right?

Earnings vs. income. Our income includes pensions, sale of stock, dividends, etc. But our earnings are 1099s, W2s, correct? So, when I am looking at withdrawing (age 65) $3000 from an IRA or SEP IRA, and I’m concerned about cap gains, I don’t pay any of those if I w/d and our “earnings” are less than $35000 correct? So, do I have to pay federal “income” tax on that money (say $3000)?